JP5470777B2 - Ferroelectric liquid crystal composition and liquid crystal display device using the same - Google Patents

Description

  The present invention relates to a smectic liquid crystal composition useful as a constituent member of a liquid crystal display element.

  The surface-stabilized ferroelectric liquid crystal display device proposed by Clark and Lagerwall et al. Has (1) high-speed response, (2) memory property, (3) wide viewing angle, (4) Since it exhibits characteristics such as being capable of passive drive, it has attracted attention as a next-generation display element.

  Unlike a nematic liquid crystal, a ferroelectric liquid crystal has a layer structure of molecules, and the molecules are tilted in the layer. In a display element using a ferroelectric liquid crystal, the transmittance of the backlight is controlled by utilizing the characteristic that the tilt angle of molecules changes with the application of voltage. Since this inclination angle has a memory property, once a voltage is applied, the inclination angle is maintained even when the voltage is turned off. The tilt angle of the molecule after turning off the voltage is called the memory angle. In order to obtain a reproducible constant transmittance after voltage application, it is necessary that the memory angle does not change. However, when a seizure phenomenon or a switching failure due to an inversion abnormality occurs in the ferroelectric liquid crystal display element, the same memory angle is not exhibited even when the same voltage is applied, so that the reproducibility of the memory angle is lowered. Further, since the memory angle immediately after the voltage is applied and the memory angle after a few minutes have elapsed since the application of the voltage change, the memory angle changes with time, and there is a problem that high-quality display cannot be performed.

In order to solve these problems, ferroelectricity is obtained by trapping ionic impurities contained in the ferroelectric liquid crystal by adding a cyclic or cage-like lipophilic or lipophilic compound to the ferroelectric liquid crystal. Although an example in which liquid crystal burn-in phenomenon and switching failure due to inversion abnormality are reduced is disclosed (see Patent Documents 1 and 2), the performance is still insufficient. Further, when the addition amount of a cyclic or cage-like lipophilic or oleophilic compound is increased for the purpose of capturing more ionic impurities, there are problems such as lowering of the transition temperature of liquid crystal and disorder of alignment.
Therefore, it has been desired to develop a means that has reproducibility of the memory angle, does not change with time, and is effective in preventing seizure phenomenon and switching failure due to reversal abnormality.

Japanese Patent Laid-Open No. 3-180815 Japanese Patent Laid-Open No. 4-227685

  The problem to be solved by the present invention is to provide a ferroelectric liquid crystal composition having a memory angle reproducibility, a memory angle that does not change with time, a burning behavior is not caused, and a preferable switching behavior is suppressed in which an inversion abnormality is suppressed. It is to be. Moreover, it is providing the manufacturing method of this ferroelectric liquid-crystal composition. Furthermore, it is providing the display element using this ferroelectric liquid-crystal composition.

  In order to solve the above problems, the present inventors have studied various additives. As a result, a display device using a ferroelectric liquid crystal composition containing a semipolar organoboron compound has reproducibility of the memory angle, and It has been found that the memory angle does not change over time, does not cause baking, and does not cause reversal abnormality, and the present invention has been completed.

  The present invention provides a ferroelectric liquid crystal composition comprising a semipolar organic boron compound and a liquid crystalline mixture, and the ferroelectric liquid crystal composition is characterized by adding a semipolar organic boron compound to the liquid crystalline mixture. A manufacturing method is provided, and a ferroelectric liquid crystal display device using the ferroelectric liquid crystal composition is also provided.

  The ferroelectric liquid crystal composition of the present invention has a reproducible memory angle, a memory angle that does not change with time, and exhibits a preferable switching behavior in which a reverse anomaly is suppressed without firing, so that display quality is improved. Can be manufactured with high productivity. The ferroelectric liquid crystal composition of the present invention is extremely useful as a constituent member of a ferroelectric liquid crystal display.

  The ferroelectric liquid crystal composition of the present invention comprises a liquid crystal mixture and a semipolar organic boron compound, but the liquid crystal mixture used is not particularly limited, and a known and commonly used liquid crystal mixture is used. Among them, the liquid crystalline mixture has the following general formula (Ia),

(In the formula, R ¹¹ and R ¹² each independently represent a linear or branched alkyl group having 1 to 18 carbon atoms, provided that at least one of the alkyl groups is a branched alkyl group. And one or two non-adjacent —CH ₂ — groups in the alkyl group are —O—, —CO—, —CO—O—, —O—CO—, —O—CO—O—. , —CH═CH—, —C≡C—, and one or more hydrogen atoms in the alkyl group may be replaced with a fluorine atom or a CN group, and A ¹ , B ¹ and Each C ¹ is independently a 1,4-phenylene group in which one or two hydrogen atoms may be replaced by a fluorine atom, a CF ₃ group, an OCF ₃ group, or a CN group, or a plurality of these groups, or It represents 1,4-cyclohexylene group, ^{a 1} is 0, 1, or 2 And, ^{b 1,} and ^{c 1} is an integer of 0 or ^1, a 1, the sum of ^{b 1} and ^{c 1} is 1 or 2.) The compound represented by the, or the following formula (I-b) ,

(In the formula, R ¹³ and R ¹⁴ each independently represent a linear or branched alkyl group having 1 to 18 carbon atoms or a fluorine atom, provided that R ¹³ and R ¹⁴ may simultaneously become a fluorine atom. And one or two non-adjacent —CH ₂ — groups are —O—, —S—, —CO—, —CO—O—, —O—CO—, —CO—S—, — S—CO—, —O—CO—O—, —CH═CH—, —C≡C—, a cyclopropylene group or —Si (CH ₃ ) ₂ — may be substituted, and one of the alkyl groups Or more hydrogen atoms may be replaced by fluorine atoms or CN groups, X ^{11 to} X ¹⁷ each independently represent a hydrogen atom, a fluorine atom, a CF ₃ group, or an OCF ₃ group, and L ^{11 to} L ¹⁴ are each independently a single bond, -O -, - S -, - CO- _{-CH 2 O -, - OCH 2} -, - CF 2 O -, - OCF 2 -, - CO-O -, - O-CO -, - CO-S -, - S-CO -, - O-CO —O—, —CH ₂ CH ₂ —, —CH═CH—, —C≡C—, and d ¹ , e ¹ , f ¹ , and g ¹ each independently represent an integer of 0 or 1, provided that d ¹ + e ¹ + f ¹ + g ¹ is 1, 2 or 3, and when d ¹ is 0, g ¹ is 0, and when d ¹ is 1, f ¹ is 0. A liquid crystalline mixture containing at least one compound selected from liquid crystal compounds is preferred.
In terms of stabilizing by widening the temperature range of the ferroelectric liquid crystal phase, the following general formula (IV),

(R ⁴¹ represents a linear or branched alkyl group having 1 to 18 carbon atoms, and one or two non-adjacent —CH ₂ — groups in the alkyl group are —O—, —CO. —, —CO—O—, —O—CO—, —O—CO—O—, —CH═CH—, —C≡C—, may be replaced by one or more of the alkyl groups In which A ⁴ , B ⁴ and C ⁴ are each independently one or two hydrogen atoms are fluorine atoms, CF ₃ groups, OCF ₃ groups, or CN 1,4-phenylene group which may be replaced by a plurality of groups, pyrazine-2,5-diyl group or pyridazine-3 in which one or two hydrogen atoms may be replaced by fluorine atoms , 6-diyl group, pyridine-2,5-diyl group, pyrimidine-2 A 5-diyl group, a trans-1,4-cyclohexylene group in which one or two hydrogen atoms may be replaced by a cyano group or a methyl group or both, or 1,3,4-thiadiazole-2, 5-diyl group, 1,3-dioxane-2,5-diyl group, 1,3-dithian-2,5-diyl group, 1,3-thiazole-2,4-diyl group, 1,3-thiazole- 2,5-diyl group, thiophene-2,4-diyl group, thiophene-2,5-diyl group, piperazine-1,4-diyl group, piperazine-2,5-diyl group, naphthalene-2,5-diyl L ⁴¹ and L ⁴² each independently represent a single bond, —O—, —CO—, —CH ₂ O—, —OCH ₂ —, —CF ₂ O—, —OCF ₂ —, —CO—. O-, -O-CO-, -O-CO-O-, -C H ₂ CH ₂ —, —CH═CH— or —C≡C— is represented, a ⁴ , b ⁴ , and c ⁴ represent 0 or 1, and the sum of a ⁴ , b ^4, and c ⁴ is 2 or 3 R ⁴² represents a single bond or a linear or branched alkylene group having 1 to 18 carbon atoms, and one or two non-adjacent —CH ₂ — groups in the alkylene group are —O -, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH = CH-, -C≡C-, and one of alkylene groups Alternatively, a compound represented by the formula (1) may be preferably used as a component of the liquid crystalline mixture.

  The ferroelectric liquid crystal composition of the present invention contains an optically active compound in order to exhibit ferroelectricity, and a known and commonly used optically active compound can be used as the optically active compound. For example, a compound having an asymmetric atom, a compound having axial asymmetry, or a compound having surface asymmetry can be used, and a compound having an asymmetric carbon or a compound having a carbon-carbon bond as an axis asymmetry is used. It is preferable that a compound having an asymmetric carbon atom is more preferable.

In an optically active compound having an asymmetric carbon, the asymmetric carbon may be introduced into a part of a chain structure or a part of a cyclic structure, and a fluorine atom or a methyl group may be present on the asymmetric carbon. Alternatively, a compound having a CF ₃ group introduced therein or a compound having an oxirane ring structure having an asymmetric carbon is preferable.
Specifically, the optically active compound is represented by the general formula (V)

(In the formula, R ⁵¹ and R ⁵² each independently represent a linear or branched alkyl group having 1 to 18 carbon atoms, and one or two non-adjacent —CH in the alkyl group. _{The 2-} group is replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O—, —CH═CH—, —C≡C—. The hydrogen atom in the alkyl group may be replaced with a fluorine atom or a CN group, and A ⁵ , B ⁵ and C ⁵ are each independently a 1,4-phenylene group, pyrazine-2,5 -Diyl group, pyridazine-3,6-diyl group, pyridine-2,5-diyl group, pyrimidine-2,5-diyl group, trans-1,4-cyclohexylene group, 1,3,4-thiadiazole- 2,5-diyl group, 1,3-dioxane-2,5-diyl group, 1,3-dithiane , 5-diyl group, 1,3-thiazole-2,4-diyl, 1,3-thiazole-2,5-diyl, thiophene-2,4-diyl group, thiophene-2,5-diyl group, piperazine- 1,4-diyl group, piperazine-2,5-diyl group or naphthalene-2,6-diyl group, provided that the hydrogen atom in the 1,4-phenylene group and naphthalene-2,5-diyl group is A fluorine atom, a CF ₃ group, an OCF ₃ group, a CN group, a CH ₃ group, or an OCH ₃ group may be substituted, and the hydrogen atom in the trans-1,4-cyclohexylene group is a CN group or CH ₃ groups may be substituted, a ⁵ , b ⁵ , and c ⁵ each independently represent 0 or 1, L ⁵¹ and L ⁵² each independently represent a single bond, —O—, —CO—, _{-CH 2 O -, - OCH 2} -, - CF 2 O -, - O _{F 2 -, - CO-O} -, - O-CO -, - O-CO-O -, - CH 2 CH 2 -, - CH = CH- or an -C≡C-, L ⁵³ is generally Formula (V-1), General Formula (V-2), or General Formula (V-3),

（式中、ｄ^５、ｅ^５、及びｆ^５は、各々独立に０以上７以下の整数を表す。）のいずれかで表される構造を有し、Z^５１は、一般式（V−４）又は一般式（V−５）、

(Wherein d ⁵ , e ⁵ , and f ⁵ each independently represents an integer of 0 or more and 7 or less), Z ⁵¹ has the general formula (V-4 ) Or general formula (V-5),

(However, Z ⁵² represents a fluorine atom, a methyl group or a CF ₃ group, R ⁵³ and R ⁵⁴ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, * Represents an asymmetric carbon). ) Is preferred.
Among the compounds represented by the general formula (V), in particular, Z ⁵¹ has a structure of the general formula (V-4) and Z ⁵² is a fluorine atom, or Z ⁵¹ has a structure of the general formula (V-5). And a compound in which R ⁵³ and R ⁵⁴ are hydrogen atoms is more preferred.
Among the compounds represented by the general formula (V), Z ⁵¹ has the structure of the general formula (V-4) and Z ⁵² is a fluorine atom. The following general formula (Vb)

(Wherein R ⁵⁷ and R ⁵⁸ each independently represents a linear or branched alkyl group having 1 to 18 carbon atoms, and one or two non-adjacent —CH in the alkyl group) _{The 2-} group is replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O—, —CH═CH—, —C≡C—. The hydrogen atom in the alkyl group may be replaced with a fluorine atom or a CN group, and L ⁵⁴ is represented by the general formula (Vb-1), or the general formula (Vb-2),

（式中、ｇ^５、及びｈ^５は、各々独立に０以上７以下の整数を表す。）のいずれかで表される構造を有する。）で表される化合物、又は、下記一般式（V−ｃ）

(Wherein, g ⁵ and h ⁵ each independently represent an integer of 0 or more and 7 or less). ) Or a compound represented by the following general formula (Vc)

（式中、Ｒ^５９及びＲ^５１０は各々独立に炭素原子数１〜１８の直鎖状又は分岐状のアルキル基を表し、ただし、該アルキル基中の少なくともどちらかひとつは分岐状のアルキル基であり、該アルキル基中の、１つ又は２つの隣接していない−ＣＨ_２−基は−Ｏ−、−ＣＯ−、−ＣＯ−Ｏ−、−Ｏ−ＣＯ−、−Ｏ−ＣＯ−Ｏ−、−ＣＨ＝ＣＨ−、−Ｃ≡Ｃ−で置き換えられてもよく、該アルキル基中の１つ以上の水素原子はフッ素原子あるいはＣＮ基で置き換えられていてもよく、X^５１及びX^５２は各々独立に水素原子あるいはフッ素原子を表し、ｄ^５は０又は１の整数を表し、L^５５は、一般式（V−ｃ−１）、一般式（V−ｃ−２）、又は一般式（V−ｃ−３）、

(In the formula, R ⁵⁹ and R ⁵¹⁰ each independently represents a linear or branched alkyl group having 1 to 18 carbon atoms, provided that at least one of the alkyl groups is a branched alkyl group. And one or two non-adjacent —CH ₂ — groups in the alkyl group are —O—, —CO—, —CO—O—, —O—CO—, —O—CO—O—. , —CH═CH—, —C≡C—, wherein one or more hydrogen atoms in the alkyl group may be replaced with a fluorine atom or a CN group, and X ⁵¹ and X ⁵² are Each independently represents a hydrogen atom or a fluorine atom, d ⁵ represents an integer of 0 or 1, and L ⁵⁵ represents a general formula (Vc-1), a general formula (Vc-2), or a general formula ( V-c-3),

(Wherein j ⁵ , k ⁵ , and m ⁵ each independently represents an integer of 0 or more and 7 or less). ).
Among these compounds, in the case of the compound represented by the general formula (Vb), R ⁵⁷ and R ⁵⁸ are more preferably a linear or branched alkyl group, and particularly preferably a linear alkyl group. On the other hand, in the case of the compound represented by the general formula (Vc), R ⁵⁹ is more preferably a linear or branched alkyl group, alkoxy group, alkenyl group or alkenyloxy group, and R ⁵¹⁰ is linear or A branched alkyl group is preferable, and a linear alkyl group is particularly preferable.

Among the compounds represented by the general formula (V), examples of compounds in which Z ⁵¹ has the structure of the general formula (V-5) as an asymmetric carbon structure and R ⁵³ and R ⁵⁴ are hydrogen atoms are shown below. I will give you.

(Wherein R ⁵³¹ is an alkyl group or alkoxy group having 4 to 14 carbon atoms, R ⁵³² is an alkyl group having 1 to 8 carbon atoms, R ⁵³³ is an alkyl group having 4 to 14 carbon atoms, L ⁵³¹ and L ⁵³² are Each independently represents a carbonyl group or a methylene group.)
Among the compounds represented by the general formula (V), examples of compounds in which Z ⁵¹ has a structure of the general formula (V-4) as an asymmetric carbon structure are given below.

(Wherein R _aa is a linear or branched alkyl group or alkoxy group having 1 to 18 carbon atoms, R _bb is a linear or branched alkyl group having 1 to 18 carbon atoms, and M _aa is the number of carbon atoms. 1 to 3 methylene groups, and M _bb represents a methylene group having 1 to 2 carbon atoms.)
When the liquid crystal mixture used in the ferroelectric liquid crystal composition of the present invention contains a cation other than lithium ions, the cation causes undesirable switching because of seizure or inversion abnormality. In order to eliminate this influence, it is desired to sufficiently purify the liquid crystal mixture or the compound that is a component of the liquid crystal mixture. At that time, for the purpose of removing impurities and the like, it is also preferable to perform a purification treatment with silica, alumina or the like. As the liquid crystalline mixture, it is preferable to use a liquid crystalline mixture having a specific resistance value of 1 × 10 ¹¹ to 1 × 10 ¹⁵ Ωcm. Considering ease of production and purification, 1 × 10 ¹¹ to 1 × 10 It is more preferable to use a liquid crystalline mixture that is ¹⁴ Ωcm. The specific resistance value of the ferroelectric liquid crystal is preferably from ^{1 × 10 10 ~1 × 10 14} Ωcm, more preferably ^{1 × 10 10 ~1 × 10 13} Ωcm. In addition to using a liquid crystal mixture with a high specific resistance as the liquid crystal mixture, the use of a liquid crystal mixture containing a cation clathrate compound in the liquid crystal mixture also prevents the influence of cations present as impurities in the liquid crystal mixture. This method is preferably used. There is no restriction | limiting in particular as a cation inclusion compound, A well-known and usual compound is used. Of these, podand, coronand, or cryptand is preferred as the compound, but the following general formula (VI),

(In the formula, Z ⁶ is an oxygen atom or a sulfur atom, a ⁶ and b ⁶ are integers greater than 0, a ⁶ + b ⁶ is 2 to 6, and X ⁶¹ and X ⁶² are the same or different groups. , Oxygen atom, sulfur atom, or the following structure,

（式中、Ｒ^６は隣り合わない−ＣＨ_２−基が、−ＣＯＯ−、−ＣＯ―、―Ｏ―、―Ｓ―、−CONH−、又は―ＣＨ＝ＣＨ−によって置換されていても良い炭素数１〜１５のアルキル基またはハロゲン化アルキル基、水素原子、シクロヘキシル基、フェニル基、ベンジル基、又はベンゾイル基である。）のいずれかの基であるか、または、X^６１、X^６２が一緒になった下記構造、

(Wherein R ⁶ is a non-adjacent —CH ₂ — group may be substituted by —COO—, —CO—, —O—, —S—, —CONH—, or —CH═CH—. An alkyl group having 1 to 15 carbon atoms or a halogenated alkyl group, a hydrogen atom, a cyclohexyl group, a phenyl group, a benzyl group, or a benzoyl group), or X ⁶¹ and X ⁶² are The following structure together,

(Wherein, Z ⁶¹ and Z ⁶² are an oxygen atom or a sulfur atom, and c ⁶ and d ⁶ are 1 or 2). ) Is more preferable.
If the association force between the cation and the cation clathrate compound present as an impurity in the liquid crystal mixture is too strong, the clathrate clathrate compound is difficult to move in both molecular weight and shape, and therefore the cation mobility deteriorates. As a result, it becomes difficult to relax the electric field formed by the cations inside the cell, which is not preferable for suppressing seizure and inversion abnormality. If there is no association force between the cation and the cation clathrate compound present as impurities in the liquid crystal mixture, the cation strongly adsorbs directly to the polar cell interface, and the cation has low solubility in the liquid crystal medium, so it strongly resists the interface. It becomes difficult to relax the electric field formed inside by the adsorbed cations. Therefore, in order to reduce the adverse effects of cations present as impurities in the liquid crystal mixture, a combination of a cation having a weak associating force and a cation inclusion compound is particularly preferred, and the cation encapsulation represented by the general formula (VI) is used. One or more of the oxygen atoms that are the source of the strong associative force of the close contact compound are replaced by nitrogen atoms that are electrically positive and consequently have the effect of appropriately weakening the association force with the cation. Compounds are particularly preferred. In such a weak association state, it is considered that the cation and the cation clathrate compound dynamically form a molecular assembly. Therefore, the cation is easily dissolved in the liquid crystal medium, and as a result, the cation mobility is also increased. It is believed to improve and prevent the formation of undesirable internal electric field due to local accumulation of cations.

  As the cation inclusion compound having a weak associating force as described above, a compound having one or two nitrogen atoms is preferably used as shown in the following structure.

Wherein R ⁶¹¹ and R ⁶¹² are not adjacent to each other by a —CH ₂ — group substituted by —COO—, —CO—, —O—, —S—, —CONH—, or —CH═CH—. And may be an alkyl group having 1 to 15 carbon atoms or a halogenated alkyl group, a hydrogen atom, a cyclohexyl group, a phenyl group, a benzyl group, or a benzoyl group, and e ⁶ is 0 or 1.)
The content of the cation inclusion compound is preferably 0.01 ppm to 10%, more preferably 0.1 ppm to 5%, and more preferably 1 ppm to 5% in terms of a mass ratio with respect to the ferroelectric liquid crystal composition. It is particularly preferred. The content of the cationic clathrates, be selected amount, such as T _AC point of the liquid crystal mixture before addition of (smectic C- smectic A phase transition temperature) does not change 10 ° C. or higher by the addition of cationic inclusion compound Is preferred.

  It is essential that the ferroelectric liquid crystal composition of the present invention contains a semipolar organic boron compound. Semipolar organoboron compounds are thought to increase the reproducibility of memory angles by suppressing local electric fields that are thought to occur in the surface of the electrode, and to suppress inversion anomalies without burning. .

  The semipolar organic boron compound generally represents an organic boron compound having a semipolar bond. Since boron is trivalent, boron forms a bond with three oxygen atoms when forming a boric acid derivative. However, a vacant electron orbital exists in the boron atom, and a lone electron pair such as an oxygen atom is coordinated in this orbital, so that the boron atom is stabilized with a special structure bonded to four oxygen atoms. Since this coordination bond is called a semipolar bond, an organic boron compound having a semipolar bond is generally called a semipolar boron compound. The semipolar organoboron compound used in the present invention is also used in this sense.

  Examples of the semipolar organoboron compound used in the ferroelectric liquid crystal composition of the present invention include di (glycerin) borate, di (glycerin) borate monovalent carboxylic acid ester, di (catechol) borate, di (1,2-propylene). Glycol) borate, di (2-ethyl-1,3-hexanediol) borate or general formula (I)

In view of compatibility with the liquid crystal composition, the number of boron atoms contained in one molecule is preferably one atom. More specifically, the formula (I-1) or (I-2)

(Wherein R ¹ and R ² are each independently a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or 2 carbon atoms) 12 alkenyloxy groups, alkyl groups having 1 to 12 carbon atoms substituted by halogen, alkoxy groups having 1 to 12 carbon atoms substituted by halogen, alkenyl groups having 2 to 12 carbon atoms substituted by halogen, or halogen Represents a substituted alkenyloxy group having 2 to 12 carbon atoms, and A ¹ and A ² each independently represent a single bond, an alkylene group having 1 to 10 carbon atoms, an aryl group having 6 to 18 carbon atoms,-(- _{(CH 2) n O-) m} - (n represents an integer of 1 to 10, m represents an integer of 1 to _{30), -. CH 2 -O} -CO-R 3 -CO- (R Represents a hydrocarbon group having 60 carbon number of 1.) Or ^{_{-CH 2 -O-CO-NH-}} R 3 represents a -NH-CO-, in each p and q independently, integer from 1 to 10 In the case where a plurality of A ¹ and A ² are present, they may be the same or different from each other.

The content of these semipolar organoboron compounds is preferably in the range of 0.01 ppm to 10%, more preferably in the range of 0.1 ppm to 1% by mass, and particularly preferably 1 ppm to 50 ppm.
It is preferable to produce a ferroelectric liquid crystal composition using a liquid crystal mixture having a specific resistance value of 1 × 10 ¹¹ to 1 × 10 ¹⁵ Ωcm, considering the ease of production and purification, It is more preferable to use a liquid crystalline mixture that is 1 × 10 ¹¹ to 1 × 10 ¹⁴ Ωcm, and it is particularly preferable to use a liquid crystalline mixture that is 1 × 10 ¹¹ to 1 × 10 ¹³ Ωcm. The ferroelectric liquid crystal composition preferably has a specific resistance value of 1 × 10 ¹⁰ to 1 × 10 ¹⁴ Ωcm, and more preferably 1 × 10 ¹⁰ to 1 × 10 ¹³ Ωcm.

  In addition, as a liquid crystalline mixture used for the ferroelectric liquid crystal of this invention, the compound represented by general formula (Ia), general formula (Ib), general formula (IV), or general formula (V) is mentioned. Although it can be used, it can widen the temperature range of the liquid crystal, maintain the transition temperature in a preferable temperature range, develop a preferable liquid crystal phase series, maintain the tilt angle in a preferable range, and perform a high-speed response. In order to reduce the viscosity as much as possible, or to keep the spontaneous polarization in a preferable range so that high-speed response is possible, there is a preferable content with respect to the entire ferroelectric liquid crystal composition. The content of the compound represented by the general formula (Ia) or (Ib) is preferably 20% to 98%, more preferably 30% to 95%, and more preferably 40% with respect to the liquid crystal mixture. -90% is particularly preferred. The content of the compound represented by the general formula (IV) is preferably 2 to 40%, more preferably 3 to 30%, and particularly preferably 4 to 20%. If the content of the compound represented by the general formula (V) is too small, the value of the spontaneous polarization becomes small and the response becomes slow. On the other hand, if the content is too large, an undesirable twist of the molecular arrangement based on the chiral effect occurs. Therefore, the content of the compound represented by the general formula (V) is preferably 1% to 40%, more preferably 3 to 30%, and particularly preferably 5 to 25%. In addition, when the content of the compound represented by the general formula (V) per compound is 1% to 10%, it is possible to suppress undesired crystallization and disorder of the phase series due to too many single components. It is still good because you can.

In the case of using a ferroelectric liquid crystal as an actual display element, the components of the liquid crystalline mixture are adjusted so that the temperature range of the (chiral) smectic C phase that is a ferroelectric phase is a wide range including room temperature. Become. Regarding the low temperature side temperature, it is preferable not to crystallize at −20 ° C., and as a display application used outdoors, it is more preferable not to crystallize at −30 ° C. For the upper temperature, T _AC point of the ferroelectric liquid crystal composition (smectic C- smectic A phase transition temperature) is preferably above room temperature, more preferably from 50 ° C. to 100 ° C.. In particular, it is preferable that the _TAC point is high for use outdoors. However, the _TAC point is determined according to a preferable temperature range of the clearing point described below. Regarding the clearing point (liquid crystal-liquid phase transition temperature) as the high temperature side temperature, the ferroelectric liquid crystal is a smectic phase, which is a liquid crystal phase close to a solid, showing ferroelectricity when producing a liquid crystal display element. It is difficult to inject liquid crystal into the display cell in this smectic phase, and it is necessary to raise the temperature to the liquid phase or nematic phase. Therefore, if the clearing point is high, there is a possibility that the liquid crystal material due to heat, the member used for the liquid crystal display element, the sealing agent, etc. may be altered, and heating and cooling require energy and time, which is not preferable as a process. Therefore, the clearing point is preferably 75 to 120 ° C, and more preferably 75 to 95 ° C as a display for indoor use. In order to obtain good alignment, it is preferable that the temperature range of the nematic phase and smectic A phase is sufficiently wide for applications other than half V-type displays. Specifically, each of the nematic phase and smectic A phase is different from each other. The temperature range shown independently without coexisting with the above phase is preferably 1 ° C. or higher, more preferably 3 ° C. or higher. In a half-V display application, in order to obtain good alignment, the smectic A phase does not exist or its temperature range is within 3 ° C, preferably within 1 ° C, and the nematic phase coexists with other phases. It is preferable that the temperature range shown independently is 1 degreeC or more, and it is more preferable that it is 3 degreeC or more.

  Further, as a component of the ferroelectric liquid crystal composition, if necessary, other than the compound represented by the general formula (Ia), the general formula (Ib), the general formula (IV), or the general formula (V) These liquid crystalline compounds can be used in combination. The compound that can be used in combination is not particularly limited, but in order to stabilize the ferroelectric liquid crystal phase, it is preferable to use a liquid crystalline compound exhibiting a smectic C phase or a chiral smectic C phase. (In this specification, the name of the liquid crystal phase includes the corresponding chiral liquid crystal phase unless otherwise specified.) In addition, the phase series of the ferroelectric liquid crystal phase or the temperature range of each liquid crystal phase is defined. In order to adjust, it is preferable to select a liquid crystal compound as appropriate. Specifically, in order to develop a nematic phase or expand the temperature range of the nematic phase, it is preferable to use a compound exhibiting a nematic phase in combination, or to develop a smectic A phase or a smectic A phase. When it is desired to expand the temperature range, it is preferable to use a compound exhibiting a smectic A phase, or, when a smectic A phase is not required, such as a half V material, a compound that does not exhibit a smectic A phase. It is preferable to use together. In order to obtain good alignment, it is necessary to stabilize the nematic phase. In that case, it is preferable to add a compound that exhibits a nematic phase having a good compatibility with the smectic liquid crystal and a wide temperature range. Such a compound preferably has a temperature range of 5 ° C. to 120 ° C. showing a nematic phase, more preferably 10 ° C. to 120 ° C., particularly preferably 20 ° C. to 120 ° C. The clearing point is preferably 70 ° C to 220 ° C. As specific examples, the following general formula (VII),

(In the formula, R ⁷⁶¹ and R ⁷⁶² each independently represent a linear alkyl group or alkoxy group having 1 to 8 carbon atoms, and A ⁷ , B ⁷ and C ⁷ are 1,4-phenylene group or 1 , 4-cyclohexylene group, a ⁷ represents 0, 1 or 2, b ⁷ and c ⁷ represent an integer of 0 or 1, and the sum of a ⁷ , b ⁷ and c ⁷ represents 1 or 2 Wherein R ⁷⁶¹ is a linear alkyl group having 1 to 8 carbon atoms when A ⁷ is a 1,4-cyclohexylene group, and R ⁷⁶² is carbon when C ⁷ is a 1,4-cyclohexylene group. A straight-chain alkyl group having 1 to 8 atoms). Among these, R ⁷⁶¹ and R ⁷⁶² are more preferably each independently a linear alkyl group having 1 to 5 carbon atoms or an alkoxy group.

  In order to obtain a display element with good contrast, it is necessary to adjust the tilt angle according to the display method. In order to increase the tilt angle, it is preferable to select a compound so as to increase the upper limit temperature of the smectic C phase or to narrow the temperature range of the smectic A phase. To reduce the tilt angle, the smectic C phase is preferred. It is preferable to use a compound that lowers the upper limit temperature of the phase or widens the temperature range of the smectic A phase.

  One kind of chiral compound may be used, or a plurality of compounds having different structures may be used. In order to suppress the helical structure in the liquid crystal phase generated based on the chiral effect and obtain a good alignment state, it is preferable to use a combination of a plurality of chiral compounds having different twist directions to be generated. At this time, if the combination of chiral compounds is selected so that the directions of spontaneous polarization are aligned, or if a combination of a compound that generates sufficiently large spontaneous polarization and a compound that induces a twisted structure but has a small spontaneous polarization value is selected, The value is preferred because it is not canceled. It is also preferable to introduce a plurality of chiral structures having different twist directions to be introduced into the same compound in order to suppress the generation of a helical structure that occurs in the liquid crystal phase based on the chiral effect. At this time, if a combination of chiral structures is selected so that the directions of spontaneous polarization are aligned, or if a combination of structures that induce sufficiently large spontaneous polarization and a torsional structure is induced but has a small spontaneous polarization value, The value is preferred because it is not canceled.

  Furthermore, a dopant such as a dye can be added to the liquid crystal composition according to the purpose. In addition, antioxidants, UV absorbers, non-reactive oligomers and inorganic fillers, organic fillers, polymerization inhibitors, antifoaming agents, leveling agents, plasticizers, silane coupling agents, etc. are added as necessary. You may do it.

  By putting the composition of the present invention in a liquid crystal cell, a liquid crystal display element can be produced. The two substrates of the liquid crystal cell can be made of a transparent material having flexibility such as glass or plastic, and one of them can be an opaque material such as silicon. A transparent substrate having a transparent electrode layer can be obtained, for example, by sputtering indium tin oxide (ITO) on a transparent substrate such as a glass plate. For the purpose of aligning the liquid crystal on the substrate, it is desirable to form a well-known liquid crystal alignment layer. As the alignment layer, an alignment layer material of polyimide or other organic polymer is formed on a substrate such as a glass substrate and then subjected to alignment treatment such as rubbing treatment, photo-alignment treatment, ion beam treatment, SiOx, CaF, etc. Formed on a substrate such as a glass substrate by vapor deposition or sputtering, or a photo-alignment layer formed by polarization irradiation, non-polarization oblique irradiation using a photo-alignment material as an alignment layer substance, or a combination of both Can be used.

  A liquid crystal display element using a ferroelectric liquid crystal can display a color without using a color filter by using a field sequential driving method, but even if a display method using a color filter is used. Good. The color filter can be prepared by, for example, a pigment dispersion method, a printing method, an electrodeposition method, or a dyeing method. A method for producing a color filter by a pigment dispersion method will be described as an example. A curable coloring composition for a color filter is applied on the transparent substrate, subjected to patterning treatment, and cured by heating or light irradiation. By performing this process for each of the three colors red, green, and blue, a pixel portion for a color filter can be created. In addition, a pixel electrode provided with an active element such as a TFT, a thin film diode, or a metal insulator metal specific resistance element may be provided on the substrate.

  The said board | substrate is made to oppose so that a transparent electrode layer may become an inner side. In that case, you may adjust the space | interval of a board | substrate through a spacer. In this case, it is preferable to adjust the thickness of the obtained cell to be 1 to 100 μm. The cell thickness is more preferably 1 to 10 μm, still more preferably 1 to 4 μm. When a polarizing plate is used, it is preferable to adjust the product of the refractive index anisotropy Δn of the liquid crystal and the cell thickness d so that the contrast is maximized. In view of manufacturing the display element, it is preferable that the cell thickness is thick. In that case, it is necessary to use a liquid crystal having a small Δn. In that case, it is desirable to use cyclohexyl or a compound having a 1,3,4-thiadiazole-2,5-diyl structure in combination. One or two cyclohexyl structures are preferably present in one molecule, and one 1,3,4-thiadiazole-2,5-diyl is preferably present in one molecule. In addition, when there are two polarizing plates, the polarizing axis of each polarizing plate can be adjusted so that the viewing angle and contrast are good. Furthermore, a retardation film for widening the viewing angle can also be used. Examples of the spacer include glass particles, plastic particles, alumina particles, and a photoresist material. Thereafter, a sealant such as an epoxy thermosetting composition is screen-printed on the substrates with a liquid crystal inlet provided, the substrates are bonded together, and heated to thermally cure the sealant.

  As a method for sandwiching the polymer-stabilized ferroelectric liquid crystal composition between two substrates, a normal vacuum injection method, an ODF method, or the like can be used. At this time, the liquid crystal composition is preferably in a uniform isotropic state or in a (chiral) nematic phase. In the smectic phase, handling during device fabrication becomes difficult.

Hereinafter, the liquid crystal composition of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In this example, the evaluation of reversal abnormality was performed according to the following procedure. Two polarizing plates were placed in crossed Nicols, the light intensity when nothing was placed in the optical path was defined as 0%, and the light intensity when placed in parallel Nicols was defined as 100%. The two polarizing plates were arranged in crossed Nicols, and the liquid crystal cell was arranged so that the light transmittance of the liquid crystal cell after applying one pulse of -5 V and 1 Hz between the two polarizing plates was minimized. One pulse of 5 V and a pulse width of 0.1 ms was applied, and the transmittance was measured. Next, after applying a rectangular wave of -5 V and 1 Hz again, a pulse with a voltage of 5 V having a different pulse width was applied, and the transmittance was measured. This was repeated, and the pulse width was sequentially changed to 5 ms, and the transmittance when each pulse was applied was measured. The pulse width when 90% of the total change in transmittance of the liquid crystal cell was changed was defined as the saturation voltage pulse width. Next, -5V, 1Hz rectangular wave is applied again, and a pulse of saturation voltage pulse width of 1.5V, which does not change the transmittance with one pulse, is applied 3000 times at 100Hz. Each transmittance before and after was measured. When a change of 0.5% or more occurred in the transmittance before and after 3000 times application, it was judged that a reversal abnormality occurred. Evaluation of image sticking is based on the pulse width (time) required to change the liquid crystal cell left in the dark state for one week from the dark state to the bright state and the pulse required to change from the initial dark state to the bright state. Evaluation was made by comparing width (time). That is, when both values were close, there was no seizure, and the greater the difference between the two values, the stronger the seizure phenomenon that occurred. The memory angle was evaluated according to the following procedure. A liquid crystal cell is installed so that the light transmittance is minimized in the molecular long axis direction under crossed Nicols, and one pulse of a rectangular wave voltage of 0.5 Hz and 10 V is applied, and the light transmittance of the liquid crystal cell is minimized. The angle was determined and designated as memory angle 1. Thereafter, one pulse of a rectangular wave having a polarity opposite to that of the memory angle 1 was applied in the same manner, and an angle at which the light transmittance of the liquid crystal cell was minimized was determined as a memory angle 2. One half of the difference between memory angle 2 and memory angle 1 was defined as the memory angle. The specific resistance value was obtained by dissolving the measurement target in toluene and measuring the specific resistance value and extrapolating the measurement target to 100%. Further, “parts” in the composition all represent “parts by mass”, and “ppm,%” indicating the content ratios are all expressed on a mass basis.
Example 1
A compound having the following structure was mixed at the ratio shown below to prepare a liquid crystal mixture (LC-1).

The specific resistance value of this liquid crystalline mixture (LC-1) was 5 × 10 ¹² Ωcm. A ferroelectric liquid crystal composition (FLC-1) was prepared by adding 20 ppm of Emalbon T-20 (manufactured by Toho Chemical Co., Ltd.) as a semipolar organic boron compound to the liquid crystalline mixture (LC-1).
The specific resistance value of this ferroelectric liquid crystal composition (FLC-1) was 5.2 × 10 ¹¹ Ωcm. Next, FLC-1 was injected into a cell having a cell gap of 2 μm that had been subjected to polyimide-rubbing treatment by a vacuum injection method to obtain a ferroelectric liquid crystal element (FLCD-1). When the memory angle was evaluated using the ferroelectric liquid crystal element (FLCD-1) thus obtained, the first measurement showed 18.0 °. Then, after applying a DC voltage of 10 V for about 10 minutes and measuring the memory angle again, it showed 18.0 ° and a reproducible memory angle was obtained. After applying a DC voltage of 10 V for 10 minutes and measuring the memory angle of the liquid crystal cell that was left for 3 minutes with the opposing electrodes of the liquid crystal cell short-circuited, the memory angle was 18.0 ° and the change over time was I couldn't see it. When LCD-1 was used to evaluate burn-in and reversal abnormality, it did not cause burn-in, and the transmittance change indicating reversal abnormality was 0.2%, which was suitable without causing reversal abnormality.

(Comparative Example 1)
Since the liquid crystal mixture (LC-1) is a ferroelectric liquid crystal having a composition similar to that of the ferroelectric liquid crystal composition (FLC-1) of Example 1 except that it does not contain Emalbon T-20, (LC -1) was used for comparison, and a ferroelectric liquid crystal device (LCD-1) was produced in the same manner as described in Example 1. When the memory angle was evaluated using the ferroelectric liquid crystal element (LCD-1) thus obtained, the first measurement showed 18.1 °. When a memory angle was measured again after applying a DC voltage of 10 V for about 10 minutes, a memory angle of 19.5 ° was shown and no reproducibility of the memory angle was observed. In addition, when a 10V DC voltage was applied for 10 minutes and then the memory angle of the liquid crystal cell left in a short-circuited state for 3 minutes was measured, the memory angle was 18.4 °, and a 10V DC voltage was applied for 10 minutes. A time-dependent change of 1.1 ° was observed compared with the memory angle immediately after. When LCD-1 was used to evaluate burn-in and reversal abnormalities, seizure occurred, and the transmittance change indicating reversal abnormalities was 7.6%, and reversal abnormalities were clearly observed. It was clear that it was inferior.
(Example 2)
A compound having the following structure was mixed at the ratio shown below to prepare a liquid crystalline mixture (LC-2).

The specific resistance value of this liquid crystalline mixture (LC-2) was 4.8 × 10 ¹² Ωcm. A ferroelectric liquid crystal composition (FLC-2) was prepared by adding 20 ppm of EB-1 (Boron International Co., Ltd.) as a semipolar organic boron compound to the liquid crystalline mixture (LC-2). The specific resistance value of this ferroelectric liquid crystal composition (FLC-2) was 2.6 × 10 ¹¹ Ωcm. A ferroelectric liquid crystal element (FLCD-2) was produced in the same manner as in Example 1. Using the ferroelectric liquid crystal element (FLCD-2) thus obtained, the memory angle was evaluated. As a result, the first measurement showed 18.2 °. Thereafter, a DC voltage of 10 V was applied for about 10 minutes, and the memory angle was measured again. As a result, it was 18.2 ° and a reproducible memory angle was obtained. After applying a DC voltage of 10 V for 10 minutes and measuring the memory angle of the liquid crystal cell left for 3 minutes with the opposing electrodes of the liquid crystal cell short-circuited, the memory angle was 18.2 ° and the change over time was I couldn't see it. When LCD-2 was used to evaluate burn-in and reversal abnormality, it did not cause burn-in, and the transmittance change indicating reversal abnormality was 0.1%, which was suitable without causing reversal abnormality.

(Comparative Example 2)
Since the liquid crystal mixture (LC-2) is a ferroelectric liquid crystal having the same composition as the ferroelectric liquid crystal composition (FLC-2) of Example 2 except that it does not contain EB-1, (LC- Using 2) for comparison, a ferroelectric liquid crystal element (LCD-2) was produced in the same manner as described in Example 1. When the memory angle was evaluated using the ferroelectric liquid crystal element (LCD-2) thus obtained, the first measurement showed 18.5 °. When a 10 V DC voltage was applied for about 10 minutes and the memory angle was measured again, it showed a memory angle of 19.7 ° and no reproducibility of the memory angle was observed. In addition, when a 10V DC voltage was applied for 10 minutes and the memory angle of the liquid crystal cell left for 3 minutes in a short-circuited state was measured, the memory angle was 18.7 °, and a 10V DC voltage was applied for 10 minutes. A change with time of 1.0 ° was observed in comparison with the memory angle immediately after. Evaluation of burn-in and reversal abnormality using LCD-2, evaluation of burn-in and reversal abnormality, seizure occurred, and transmittance change indicating reversal abnormality was 4.6%, clearly A reversal abnormality was observed and was clearly inferior to Example 2.
(Example 3)
A compound having the following structure was mixed at the ratio shown below to prepare a liquid crystalline mixture (LC-3).

The specific resistance value of this liquid crystalline mixture (LC-3) was 6.2 × 10 ¹² Ωcm. As a semipolar organic boron compound, 10 ppm of EB-1 was added to this liquid crystal mixture (LC-3) to produce a ferroelectric liquid crystal composition (FLC-3).

The specific resistance value of this ferroelectric liquid crystal composition (FLC-3) was 1 × 10 ¹¹ Ωcm. A ferroelectric liquid crystal element (FLCD-3) was produced in the same manner as in Example 1. Using the ferroelectric liquid crystal element (FLCD-3) obtained in this way, the memory angle was evaluated. As a result, the first measurement showed 25.2 °. Then, after applying a DC voltage of 10 V for about 10 minutes and measuring the memory angle again, it showed 25.2 ° and a reproducible memory angle was obtained. After applying a DC voltage of 10 V for 10 minutes, the memory angle of the liquid crystal cell that was left for 3 minutes with the opposing electrodes of the liquid crystal cell short-circuited was measured. As a result, the memory angle was 25.2 ° and the change with time was I couldn't see it. When LCD-3 was used to evaluate burn-in and reversal abnormality, it did not cause burn-in, and the transmittance change indicating reversal abnormality was 0%, which was suitable without causing reversal abnormality.

(Comparative Example 3)
Since the liquid crystal mixture (LC-3) is a ferroelectric liquid crystal having a composition similar to that of the ferroelectric liquid crystal composition (FLC-3) of Example 3 except that it does not contain EB-1, (LC- Using 3) for comparison, a ferroelectric liquid crystal device (LCD-3) was produced in the same manner as described in Example 1. Using the ferroelectric liquid crystal element (LCD-3) thus obtained, the memory angle was evaluated. As a result, the first measurement showed 25.3 °. When a memory angle was measured again after applying a DC voltage of 10 V for about 10 minutes, a memory angle of 26.7 ° was shown and no reproducibility of the memory angle was observed. Also, when a 10V DC voltage was applied for 10 minutes and then the memory angle of the liquid crystal cell left in a short-circuited state for 3 minutes was measured, the memory angle was 25.6 °, and a 10V DC voltage was applied for 10 minutes. A time-dependent change of 1.1 ° was observed compared with the memory angle immediately after. Evaluation of burn-in and reversal abnormality using LCD-3, evaluation of burn-in and reversal abnormality, seizure occurred, and the transmittance change indicating reversal abnormality was 10.5%, clearly A reversal abnormality was observed and was clearly inferior to Example 3.
Example 4
10 ppm of EB-1 as a semipolar organic boron compound and a compound (I-aa) having the following structure as a cation inclusion compound in the liquid crystalline mixture (LC-1) described in Example 1;

Was added to prepare a ferroelectric liquid crystal composition (FLC-4). The specific resistance value of this ferroelectric liquid crystal composition (FLC-4) was 2 × 10 ¹¹ Ωcm. A ferroelectric liquid crystal element (FLCD-4) was produced in the same manner as in Example 1. Using the ferroelectric liquid crystal element (FLCD-4) thus obtained, the memory angle was evaluated. As a result, the first measurement showed 24.9 °. Then, after applying a DC voltage of 10 V for about 10 minutes and measuring the memory angle again, it showed 24.9 ° and a reproducible memory angle was obtained. When a 10V DC voltage was applied for 10 minutes and the memory angle of the liquid crystal cell left for 3 minutes with the opposing electrodes of the liquid crystal cell shorted was measured, the memory angle was 24.9 °, and the change over time was I couldn't see it. When LCD-4 was used to evaluate burn-in and reversal abnormality, it did not cause burn-in, and the transmittance change indicating reversal abnormality was 0%, which was suitable without causing reversal abnormality.

Claims (7)

General formula (I) as a semipolar organoboron compound

A ferroelectric liquid crystal composition comprising at least one compound having a skeleton represented by formula (1), wherein the number of boron atoms in one molecule of the semipolar organic boron compound is 5 or less. General formula (I-1) or general formula (I-2) as a semipolar organic boron compound

(Wherein R ¹ and R ² are each independently a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or 2 carbon atoms) 12 alkenyloxy groups, alkyl groups having 1 to 12 carbon atoms substituted by halogen, alkoxy groups having 1 to 12 carbon atoms substituted by halogen, alkenyl groups having 2 to 12 carbon atoms substituted by halogen, or halogen Represents a substituted alkenyloxy group having 2 to 12 carbon atoms, and A ¹ and A ² each independently represent a single bond, an alkylene group having 1 to 10 carbon atoms, an aryl group having 6 to 18 carbon atoms,-(- _{(CH 2) n O-) m} - (n represents an integer of 1 to 10, m represents an integer of 1 to _{30), -. CH 2 -O} -CO-R 3 -CO- (R Represents a hydrocarbon group having 60 carbon number of 1.) Or ^{_{-CH 2 -O-CO-NH-}} R 3 represents a -NH-CO-, in each p and q independently, integer from 1 to 10 The ferroelectric liquid crystal composition according to claim 1 , wherein the ferroelectric liquid crystal composition comprises a compound represented by the formula: wherein, when a plurality of A ¹ and A ² are present, they may be the same or different. The ferroelectric liquid crystal composition has the following general formula (Ia)

(In the formula, R ¹¹ and R ¹² each independently represent a linear or branched alkyl group having 1 to 18 carbon atoms, provided that at least one of the alkyl groups is a branched alkyl group. And one or two non-adjacent —CH ₂ — groups in the alkyl group are —O—, —CO—, —CO—O—, —O—CO—, —O—CO—O—. , —CH═CH—, —C≡C—, and one or more hydrogen atoms in the alkyl group may be replaced with a fluorine atom or a CN group, and A ¹ , B ¹ and Each C ¹ is independently a 1,4-phenylene group in which one or two hydrogen atoms may be replaced by a fluorine atom, a CF ₃ group, an OCF ₃ group, or a CN group, or a plurality of these groups, or It represents 1,4-cyclohexylene group, ^{a 1} is 0, 1, or 2 And, ^{b 1,} and ^{c 1} is an integer of 0 or ^1, a 1, the sum of ^{b 1} and ^{c 1} is 1 or 2.) The compound represented by the, or the following formula (I-b) ,

(In the formula, R ¹³ and R ¹⁴ each independently represent a linear or branched alkyl group having 1 to 18 carbon atoms or a fluorine atom, provided that R ¹³ and R ¹⁴ may simultaneously become a fluorine atom. And one or two non-adjacent —CH ₂ — groups are —O—, —S—, —CO—, —CO—O—, —O—CO—, —CO—S—, — S—CO—, —O—CO—O—, —CH═CH—, —C≡C—, a cyclopropylene group or —Si (CH ₃ ) ₂ — may be substituted, and one of the alkyl groups Or more hydrogen atoms may be replaced by fluorine atoms or CN groups, X ^{11 to} X ¹⁷ each independently represent a hydrogen atom, a fluorine atom, a CF ₃ group, or an OCF ₃ group, and L ^{11 to} L ¹⁴ are each independently a single bond, -O -, - S -, - CO- _{-CH 2 O -, - OCH 2} -, - CF 2 O -, - OCF 2 -, - CO-O -, - O-CO -, - CO-S -, - S-CO -, - O-CO —O—, —CH ₂ CH ₂ —, —CH═CH—, —C≡C—, and d ¹ , e ¹ , f ¹ and g ¹ each independently represent an integer of 0 or 1, provided that d ¹ + e ¹ + f ¹ + g ¹ is 1, 2 or 3, and when d ¹ is 0, g ¹ is 0, and when d ¹ is 1, f ¹ is 0. 3. The ferroelectric liquid crystal composition according to claim 1, wherein the ferroelectric liquid crystal composition is a liquid crystal mixture containing at least one compound from liquid crystal compounds. Ferroelectric ferroelectric liquid crystal composition according to any one of claims 1-3 in which the liquid crystal composition is characterized by exhibiting ferroelectric properties. Specific resistance ^{1 × 10 10 ~1 × 10 14} Ωcm ferroelectric liquid crystal composition according to any one of claims 1 to 4. Ferroelectric liquid crystal composition according to any one of claims 1 to 5 the content of semi-polar organic boron compound is 0.01ppm~10%. The liquid crystal display device using a ferroelectric liquid crystal composition according to any one of claims 1 to 6.